Regular intake of supplements containing omega-3 fatty acids may support the function of blood vessels in cardiovascular patients, suggests a new Chinese meta-analysis.
The meta-analysis included data from 16 randomized controlled trials and a total of 901 participants who used omega-3 fatty acid supplement doses from 0.45 to 4.5 grams per day for an average of 56 days (1). The analysis showed that, compared to placebo, regular supplement intake was associated with a 2.3% improvement in flow-mediated dilation (FMD), a measure of a blood vessel’s healthy ability to relax. Signs of the potential benefits of these fatty acids were limited to people with cardiovascular disease or its risk factors. No benefits were observed in healthy participants. The researchers commented that this could be partly explained in that healthy individuals may already have sound endothelial function, and the improve-ment due to omega-3 fatty acid supplementation was thus limited.
While the effect on FMD was significant, no effects were observed for endothelium-independent vasodilation (EIV). This indicates that omega-3 fatty acids benefit the cells lining the blood vessels (endothelium) directly. The researchers noted that the potential mechanism was still unknown, but the findings pointed to a potential role for omega-3 fatty acids reducing levels of the inflammatory biomarkers that are involved in damage to cells, called soluble adhesion molecules. Their conjecture is in agreement with recent studies that reported omega-3 fatty acids may counter the atherosclerotic and carcinogenic effects of an intercellular adhesion molecule (2,3). The scientists concluded that although a positive association was identified between omega-3 fatty acids and endothelial function, the evidence for a clinical efficacy was not strong enough to make final recommendations concerning specific doses or durations of supplementation for different populations. They recommended conducting future well-designed studies to identify the target population for omega-3 fatty acid supplementation and to determine the optimal dose.